6,627 research outputs found

    Measuring the Cost-effectiveness of Conservation Auctions Relative to Alternate Policy Mechanisms

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    The principle motivation for using price-discriminating conservation auctions is that they are expected to be significantly more cost-effective than fixed-price mechanisms. This paper measures cost effectiveness for tenders from two rounds of the Auction for Landscape Recovery in Western Australia relative to counterfactual fixed-price mechanisms. If we assume that the bid equals the compliance cost, the auction gives a significant cost saving over fixed-price mechanisms. If instead we assume that bids include an element of rent, fixed-price mechanisms can be more cost effective than the auction. The significance of these results is that a fixed price scheme may achieve a similar level of cost effectiveness to a conservation auction, when one or more of the following apply: compliance costs do not vary significantly between producers, auction bids have a significant element of rent and the auction incurs a significant additional administrative cost.Auctions, conservation, bio-diversity, Environmental Economics and Policy, Q57,

    Estimating Urban Residential Water-Demand With Increasing Block Prices: The Case of Perth, Western Australia

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    This study uses panel data at suburb level to estimates the elasticity water demands in Perth, Australia from 1995 to 2005. After deriving the consumer’s water demand under a non-linear budget constraint, we estimate the water demand model, which accounts for how water (and other purchased goods) is used to satisfy fundamental desires of the household. We have applied the specification of price that provided the correctly estimated marginal price from the block tariff structure, and employed a maximum likelihood estimation technique to tackle the endogeneity and heteroskedasticity issues. Our estimation of water demand price elasticities are slightly higher (more elastic) than previous study in Perth, but broadly in line with other estimates in the literature.water demand, water pricing, block pricing, water resource management, household model, Demand and Price Analysis, Resource /Energy Economics and Policy, Q21, Q25 and Q23,

    The galactic dynamo and its relation to the propagation of ultra-high-energy cosmic rays

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    The problem of the origin and nature of the galactic magnetic field is of fundamental interest. The astrophysical consequences of this field are far-reaching, being particularly relevant to the unsolved problem of the origin of cosmic rays. An analysis is made of the small-scale and large-scale feature, of the distribution of arrival directions of ultra-high-energy cosmic rays in the hope of deducing information about their sources and the strength and degree of irregularity of galactic and intergalactic oiagnetic fields. The outcome of these statistical searches is negative. After a review of the basic ideas of the turbulent dynamo, techniques are developed for performing numerical experiments upon the galactic dynamo. The results of these experiments indicate that dynamo action can occur in the galaxy and a steady solution is most easily excited. The dependence of the models upon boundary conditions and relevant astrophysioal parameters is investigated. An attempt is made to simulate the nonlinear effect of suppression of turbulence by the magnetic field, which is incorporated into the model proposed for the Galaxy. The propagation of ultra-high-energy cosmic rays is examined for this . model. It is found that these particles cannot be of Galactic origin if they are protons, in agreement with the results obtained from conventional field models. Comparisons are made between the predictions of the dynamo models and the observed synchrotron radiation from the Galaxy and external galaxies which shed some light upon the nature of the intergalactic medium

    Space group symmetry fractionalization in a chiral kagome Heisenberg antiferromagnet

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    The anyonic excitations of a spin-liquid can feature fractional quantum numbers under space-group symmetries. Detecting these fractional quantum numbers, which are analogs of the fractional charge of Laughlin quasiparticles, may prove easier than the direct observation of anyonic braiding and statistics. Motivated by the recent numerical discovery of spin-liquid phases in the kagome Heisenberg antiferromagnet, we theoretically predict the pattern of space group symmetry fractionalization in the kagome lattice chiral spin liquid. We provide a method to detect these fractional quantum numbers in finite-size numerics which is simple to implement in DMRG. Applying these developments to the chiral spin liquid phase of a kagome Heisenberg model, we find perfect agreement between our theoretical prediction and numerical observations.Comment: 5 pages plus appendi

    Discovery of a Classic FR-II Broad Absorption Line Quasar from the FIRST Survey

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    We have discovered a remarkable quasar, FIRST J101614.3+520916, whose optical spectrum shows unambiguous broad absorption features while its double-lobed radio morphology and luminosity clearly indicate a classic Fanaroff-Riley Type II radio source. Its radio luminosity places it at the extreme of the recently established class of radio-loud broad absorption line quasars (Becker et al. 1997, 2000; Brotherton et al. 1998). Because of its hybrid nature, we speculate that FIRST J101614.3+520916 is a typical FR-II quasar which has been rejuvenated as a broad absorption line (BAL) quasar with a Compact Steep Spectrum core. The direction of the jet axis of FIRST J101614.3+520916 can be estimated from its radio structure and optical brightness, indicating that we are viewing the system at a viewing angle of > 40 degrees. The position angles of the radio jet and optical polarization are not well-aligned, differing by 20 to 30 degrees. When combined with the evidence presented by Becker et al. (2000) for a sample of 29 BAL quasars showing that at least some BAL quasars are viewed along the jet axis, the implication is that no preferred viewing orientation is necessary to observe BAL systems in a quasar's spectrum. This, and the probable young nature of compact steep spectrum sources, leads naturally to the alternate hypothesis that BALs are an early stage in the lives of quasars.Comment: 14 pages, 6 postscript figures; accepted for publication in the Astrophysical Journa

    A catalog of Nearby Poor Clusters of Galaxies

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    A catalog of 732 optically selected, nearby poor clusters of galaxies covering the entire sky north of −3∘\rm -3^{\circ} declination is presented. The poor clusters, called WBL clusters, were identified as concentrations of 3 or more galaxies with photographic magnitudes brighter than 15.7, possessing a galaxy surface overdensity of 104/310^{4/3}. These criteria are consistent with those used in the identification of the original Yerkes poor clusters, and this new catalog substantially increases the sample size of such objects. These poor clusters cover the entire range of galaxy associations up to and including Abell clusters, systematically including poor and rich galaxy systems spanning over three orders of magnitude in the cluster mass function. As a result, this new catalog contains a greater diversity of richness and structures than other group catalogs, such as the Hickson or Yerkes catalogs. The information on individual galaxies includes redshifts and cross-references to other galaxy catalogs. The entries for the clusters include redshift (where available) and cross-references to other group and cluster catalogs.Comment: 27 pages, 7 figures, + one 20-page landscape table, accepted for publication in A
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